Talking about how bronies act in the context of this forum is quite explicitly banned, because I honestly can't think of anything related to that except past drama. And the currently active mods and community forts, I suppose, but that discussion should be regulated to those threads. Not here.
What, pray tell, DO you want to talk about? It better not just be how people are annoying, because there's a nice shiny report button for that. Any real discussion really is better suited for over there, whether you're a fan or not.
As for the other forum's "officialness," it's entirely unofficial. That a large portion (100%) comes from these forums is very relevant, though. It's quite related to these forums, most notably it is where you should direct any discussion not allowed here.
I suspect you just want to disassociate yourself from ponies in general. Let me just say, anyone who associates you with something (doesn't matter if it's ponies or anything else) without consulting you first is a douchebag and not worth your time. Registering for that forum will not irrevocably tarnish your soul, either. Fears of association are unfounded, because no one's going to assume you're a brony unless they're a jerk, and thus it's a great way to spot jerks and avoid them.
Long story short, if you have anything worthwhile to say, there's a forum for that. If you don't have anything worthwhile to say, well, don't say it.